Anti Gravity Eddy Current Machine!

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My Dad has an awesome background of science, when I saw the science contest I asked him for ideas on what to do - the result is Eddy currents.

In this 'ible you should learn what an eddy current is and how they occur and how to make them yourself!

I'm sorry for the lack of photos, you can't exactly photograph an electrical current...

Parts list is explained further in the 'ible where I show you how to make this neat machine yourself.

Move on for the full experience!

**Before you comment and say "This is not ANTI-GRAVITY" please read the following:

Anti = Against, Opposed to, Prejudicial to, Preventing, Counteracting, or Mitigating.

Gravity = the force that attracts a body towards the centre of the earth, or towards any other physical body having mass.

Anti in short is Opposed to.

Gravity in short is a downwards force.

Anti-Gravity is a term used for an object that is Opposed to a downward force (thus slowing down gravity).

Step 1: The What, When, Where and Why of Eddy Currents

"Eddy currents (also called Foucault currents) are circular electric currents induced within conductors by a changing magnetic field in the conductor, due to Faraday's law of induction. Eddy currents flow in closed loops within conductors, in planes perpendicular to the magnetic field." ~Quote from wiki~

My dad has taught me to question everything with five simple words; Who, What, When, Where and Why?

Using this principle lets briefly explain eddy currents.

Who: François Arago

What: Eddy Current

When: 1851

Where:Beginning in 1933, in Germany, while working for the
Kaiser-Wilhelm-Institute, Professor Friedrich Förster adapted eddy current technology to industrial use, developing instruments for measuring conductivity and for sorting mixed-up ferrous components.

Why: To develop an instrument for measuring conductivity and for sorting mixed-up ferrous components.

So there you have it, the "who, what, where and Why" of eddy currents.

Now move on to the next step for my explanation of these wondrous marvels!

Step 2: My Explanation.

So from what I understand, eddy currents are the following:
When a strong magnet passes through a tube of non-ferric metal (meaning the magnet won't stick) but this metal is conductive (i.e. copper, aluminium and brass).

When the magnet passes though the conductive-non-ferric material it creates electricity.

This electricity occurs in invisible waves that separate at the middle of the magnet, half going up and half going down.

The half of the currents that go down the tube ahead of the magnet loop back around and in the end they go up too.

In turn, the down-up currents push the magnet back up the tube thus making it fall at an extremely slow rate.

When the electrical currents push the magnet back up the tube the magnet can take over 20X the time to fall to the ground as a normal object.

The tube wall size also makes a difference, the thicker the wall - the slower the fall!

We have used a 3mm walled alloy tube and it took 20X longer to fall through the tube!

Eddy currents can also work if you drop a strong magnet onto a slab of conductive but non-ferric material, the magnet falls at high speed and then when it approaches the slab it slows right down and lands quite softly.

If you don't understand any of this please PM me and I will try to help.

Lets move on to where you can make your own eddy currents!

Step 3: The Gear I'm Using.

Here is a step dedicated to the gear I used.

I had a 30cm (1') (12") tube of aluminium.

I also had 1.5cm Neodymium magnet.

The third photo shows the time to drop, less than one second out of the tube and three seconds through the tube! 3 times longer with the eddy currents!

The next step will tell you how to set the effect up!

Step 4: D.I.Y. (Do It Yourself) Eddy Currents.

Here's how to make eddy currents in your own home.

You will need either a neodymium or strontium magnet of a decent size.

You will also need a conductive but non-ferric material (preferably a tube).

Now you have to make sure the magnet will fit in the tube without touching the edges, there should be about a millimeter around the edges of the magnet.

Now with the end of the tube over a soft landing (rag, couch, bed, mattress, pillow or any other soft thing) you can drop the magnet through the tube - BUT - First you should drop it outside of the tube to test the difference!

You should notice the magnet moves much much slower through the tube and you can even drop marbles down the tube to eliminate the displacement theory.

Thanks for reading, If you know anyone that might have a possibility of interest in this topic please send them the link!

***UPDATE***

I have now added a video to this 'ible, Many thanks to : BWRUSSELL for providing me with the URL so I could embed my video.

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28 Discussions

Would you be interested in designing a maglev using eddy currents to transport1000 people over a distance of 37x 3.3 mters?

I like the way you approach the "problem" but statement of "Anti Gravty" is simply wrong.

All that happens is that the magnet induced a current in the pipe due to it's movement.

This current in return produces an magnetic field in the pipe wich is opposite to the one from the magnet.

No anti gravity, no magic, just electricty and magnetic fields.

And if you make a definition of anti gravity you should stick to the fact.

The term gravity defines something else than magnetic fields and electricity, otherwise we could call every plane or hot air balloon an anti gravity machine ;)

Man, I have been waiting for this comment, it is an easy explanation as to why I am correct.

Lets use Wiki as out definition base:

antigravity

antɪˈɡravɪti/

nounPhysics

noun: anti-gravity

1. 1.
a hypothetical force opposing gravity.

Then we look at opposing:

opposing

əˈpəʊzɪŋ/

Facing; opposite.

"on the opposing page there were two addresses"

And you are right, every plane, hot air balloon and other flying things are anti-gravity :)

The fact is that they work against gravity (thus making them fly) so the statement anti-gravity isn't all that special!

I am going to refine my other idea a little better for you.

The way things are supposed to work in science is first you have an observation of something happening, which is what you did start with, so that is good. You notice there is something happening that is different. You need to verify that the results of your observations are reproducible and not just a one time fluke. In other words anyone else reading the description should be able to do the same thing. After you have that done then you propose a reason or explanation for what is happening. This is the theory part. In your case the theory was provided by the research and you state it. So a good theory would be an acceptable explanation of what you have observed.

Now you move into the final phase, and this is the one I am suggesting that you do, and that is the experimental phase. You devise a way of testing your theory to see if it is correct. There is a very big difference between theoretical science and experimental science. Theoretical people will say that "this is the way we believe something works and it meets all the standards as we know them." The experimental scientist says "yeah, prove it." And they devise methods and machines for testing the theories to see if they do hold up.

Now what I suggested you do is find a way of actually observing the effect that you think is happening.

If you use iron filings you should be able to show there is a difference. It is not the area right next to the tube you are interested in as you noted all the filings would just bunch up. Its the fringe area that you will see results. If you spread out a fine and even field of filings and draw a magnet through them the ones closest to the magnet will stick to it but farther out where it is to weak to pull them in it will align them showing the direction that the field was moving in as you moved that magnet. It should all be uniform. However if the magnets in the tube are indeed creating magnetic fields in the pipe and those are moving as the magnets pass through you should see a very different pattern. I suspect it will look more like swirls rather than what a magnet alone can make. Doing all of this would give you experimental evidence to back up your claim and the entire thing should be reproducible by any other party that wants to try it to verify it.

Finally, you need to use a consistent propellent so each run through the tube is the same. For that you can use some kind of bellows with a set weight falling on it from a set distance. That will produce a consistent force. In order to refine the experiment you can try varying the force so you have different velocities.

Finally to make the whole thing more interesting after you have done all that try running a DC voltage through the pipe and see if it produces changes. Run it in both directions and at various voltages and amperages. That should make things even more interesting. Then try and rxplain your results.

7 replies

Wow, that is a lot of testing!

I would love to do it but at this point in time the video at the end is the best I can do.

Maybe if I had a workshop I would get the required stuff and build it!

If you have the ability to test it further, go ahead!

The pattern of the waves is gained from Wiki and I have re-drawn them to keep the content mine, the effect is 100% repeatable so if you have any copper tube and a strong magnet it will fall at a reduced gravity like shown in my video.

Air pressure causes them to spin in the tube like a bullet along a rifled barrel, so after some thought, I came up with an equal weight pulling the magnets through the tube. The tube would rest in a grooved piece of wood, with paper to show the iron filing movement.

Now, that is an interesting rig!

I should have a go at setting it up sometime.

The main problem is that if the magnet touches the tube the effect nearly stops.

Yet another test to prove, theory being that it shorts out the current flow. Use electrical tape to insulate it. Then a conducting tape (foil tape) and compare the difference.

Wow, this is getting beyond me now!

Wikipedia says they are called "eddy currents" because the electrical flow looks like that of oars being swung through water. (that which I have done many times before).

Good refinement, the weight would give consistent g acceleration whereas air power might vary a lot even depending atmospheric conditions and pressure build up in the pipe.

By the way, a large aluminum pepper shaker would work great for making a fine even dusting of iron filings.

FYI. You can host the video on Youtube for free and then embed it in the body of your Instructable. Much more user friendly.

3 replies

That is the obvious thing to do but unfortunately I don't have an account.

The account is free as well. You should have an email address if you have an account here.

Unless I am using my parent's email account and they don't want me signing up to many different things with it.